The invention generally relates to ports for containers and more specifically relates to wedge-shaped ports for flexible containers.
It is common medical practice to provide fluids to a patient either intravenously or enterally as a method of treating a patient for various medical conditions. Frequently, the fluids to be administered to a patient are contained in a flexible container. One method of forming a flexible container is to seal two sheets of flexible material about the periphery of the sheets to create a cavity. A port is frequently placed between the sheets during the sealing process to create a communication between the cavity and the exterior of the container to provide a means of introducing fluid into or dispensing fluid from the container. In many cases, a length of flexible tubing is typically attached to this port so that a needle or enteral feeding tube can then be attached to the other end of the tube to administer the fluid to the patient.
Generally speaking, fluids that are administered to a patient must be sterile. Therefore, it is very important that a hermatic seal is created between the port and the container. Certain medical solutions that are administered to patients such as high concentrations of dextrose, amino acids, lipid emulsions, or enteral diets are also oxygen sensitive. Therefore, in those cases, it is also very important that the container and the port are manufactured from materials that reduce permeability of the container, or as an alternative, an overwrap is placed over the container at the time of manufacture to reduce permeability of the container.
Typically fluids to be administered to a patient are added to a flexible container through the use of an access port into the container. A separate port is frequently provided to administer the fluid to the patient. In the past, these ports have been typically formed by placing a tube in between the sheets of the container as the container is manufactured. The tubes are sealed to both sheets of the container during manufacture. Since the tubes have a cylindrical shape and the sheets are basically flat, stresses and thinning occur in the sheets as the sheets are sealed about each tubular port. One means of reducing the stresses created by sealing a tubular port to the sheets of a flexible container is to design the port to have an lenticular rather than cylindrical configuration.
One problem with each of the examples described above, however, is that thinning and stressing of the sheets continues to occur as the flat sheets are forced to seal about a curved port. As long as the material used to create the container is fairly elastic and capable of withstanding stresses, then it is possible to develop an adequate seal between a curved port and a flat sheet. However, in many cases, it is desired to use materials which are relatively inelastic or are very thin and thus more susceptible to stress fractures at the location of the seal of the material to the curved port.